1. Field of the Invention
The present invention relates to radiation curable coating compositions, methods of coating substrates with the coating compositions, and substrates coated with the coating compositions.
2. Description of Related Art
Many currently available radiation curable coatings, such as those cured with ultra-violet (“UV”) radiation or electron beam (“EB”) radiation, have a tendency to be inflexible after curing and prone to high levels of shrinkage. Consequently, many radiation curable coatings are recognized to be inadequate in terms of direct to metal adhesion, formability and retort resistance, which are some of the desired properties for rigid packaging coating applications. Adhesion and extensibility inadequacies have been found when the coatings were used for flexible packaging.
Commonly-owned International Patent publication WO 2008/151286 describes radiation curable oligomers prepared from an epoxidized vegetable oil and a hydroxyl functional material in the presence of a strong acid catalyst.
The radiation curable coating compositions of the invention aim to solve some of the aforementioned inadequacies. The coating compositions can be used, inter alia, as packaging coatings for food and beverage packaging and containers. They can be formulated to provide improved adhesion, flexibility, and formability compared to some commercial radiation curable coating compositions.